Possible Causes
WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
DTC 84/B1161 could be caused by an open in circuit ICR+ (Yellow/Violet wire) and circuit ICR- (Yellow/Orange wire) in right side head impact air bag squib circuit, right side head impact air bag squib malfunction or air bag sensor assembly malfunction.
NOTE:
During testing, if DTCs other than DTC 84/B1161 are displayed, disregard them.